Trimethylaminuria (TMAU) is also known as fish odor syndrome or fish malodor syndrome. It is a rare metabolic disorder that interupts the normal production of the enzyme Flavin containing monooxygenase 3 (FMO3). When FMO3 is not working correctly or if there is not enough enzyme, the body loses the ability to properly breakdown trimethylamine (TMA) from compounds found in food into trimethylamine oxide (TMAO). Trimethylamine then builds up and is released in the person's sweat, urine, and breath, giving off a strong fishy odor.

The first clinical case of TMAU was described in 1970 in the medical journal The Lancet, but literary references go back more than a thousand years. Hindu folklore mentions in the epic Mahabharata (compiled around 400 AD) a maiden who "grew to be comely and fair, but a fishy odor ever clung to her."

Some people with trimethylaminuria have a strong odor all the time, but most have a moderate smell that varies in intensity over time. Individuals with this condition do not have any physical symptoms, and typically appear healthy. The condition seems to be more common in women than men. Scientists suspect that female sex hormones, such as progesterone and/or estrogen, aggravate symptoms. There are several reports that the condition worsens around puberty. In women, symptoms can worsen just before and during menstrual periods, after taking oral contraceptives, and around menopause.

Most cases of trimethylaminuria appear to be genetically inherited. But, this odor varies depending on many known factors, including diet, hormonal changes, other odors in the space, and individual sense of smell. What to do?

Taking low doses of antibiotics to reduce the amount of bacteria in the gut

Using slightly acidic detergents with a pH between 5.5 and 6.5

At least one study* has suggested that the daily intake of charcoal and/or copper chlorophyllin may be of significant use in improving the quality of life of individuals suffering mild forms of TMAU, the success rates vary:

85% of people tested completely lost their "fishy" odor

10% partially lost their odor

5% kept the scent

While this study sounds very positive, many people in trimethylaminuria support groups who have tried charcoal and copper chlorophyllin have not experienced the same benefit.

But, knowing that activated charcoal is rated "Safe & Effective" by the FDA, and knowing that activated charcoal is used in thousands of applications to remove offensive or dangerous odors, scents, gases, it makes perfect sense to give this simple and natural remedy a try, while being careful to avoid the above products that may contribute to TMAU.